Function fetchCommitMetasParallel

tools/flakereport/bisect.go:479–506

fetchCommitMetasParallel fetches commit metadata for a list of SHAs concurrently, bounded by maxConcurrency. Returns an immutable map of SHA → CommitMeta; failed fetches are logged and omitted (heuristic priors fall back to 1.0).

(ctx context.Context, repo string, shas []string, maxConcurrency int)

// bounded by maxConcurrency. Returns an immutable map of SHA → CommitMeta; failed
// fetches are logged and omitted (heuristic priors fall back to 1.0).
func fetchCommitMetasParallel(ctx context.Context, repo string, shas []string, maxConcurrency int) map[string]CommitMeta {
	metas := make([]CommitMeta, len(shas))
	ok := make([]bool, len(shas))

	g, ctx := errgroup.WithContext(ctx)
	g.SetLimit(maxConcurrency)
	for i, sha := range shas {
		g.Go(func() error {
			meta, err := fetchCommitMeta(ctx, repo, sha)
			if err != nil {
				fmt.Printf("Warning: failed to fetch metadata for commit %s: %v\n", sha[:7], err)
				return nil
			}
			metas[i] = meta
			ok[i] = true
			return nil
		})
	}
	_ = g.Wait()

	commitMetas := make(map[string]CommitMeta, len(shas))
	for i, sha := range shas {
		if ok[i] {
			commitMetas[sha] = metas[i]
		}
	}
	return commitMetas
}